Atrial fibrillation is one of the most common heart arrhythmias in the world, affecting over 2.5 million people in the United States alone. Ablation of cardiac tissue to create scar tissue that interrupts the path of the errant electrical impulses in the heart tissue is one method for treating cardiac arrhythmia. Such ablation may take the form of one or more lines or points of ablation of heart tissue, to a series of ablations that form a strategic placement of ablation lines in, around or in proximity to one or both atria to stop the conduction and/or formation of errant impulses.
More particularly, the pattern of ablation lines may be similar to the pattern of surgical lines that are created in the so-called “Maze” procedure, which was first developed as an open chest procedure. To reduce the trauma associated with the Maze surgical procedure, substantial efforts have been made to achieve similar results via less invasive ablation techniques. Among other things, the Maze procedure includes a series of transmural ablations or lesions to be formed on the atrium in the vicinity of the pulmonary veins. A series of lesions that may be made during the Maze procedure are shown in various prior patents or articles such as U.S. Pat. Nos. 6,517,536 and 6,546,935, both to Hooven and assigned to AtriCure, Inc.